In extreme ultraviolet (EUV) lithography, EUV radiation is generated by irradiating a tin droplet with a laser beam. A reticle (or mask) for a lithography apparatus may be used for patterning a pattern in a substrate (i.e., wafer) using EUV radiation. Next to the reticle, reflective optical elements known as fiducial marks are used for alignment the wafer to the reticle and/or controlling the dose of the EUV radiation source. Also close to the reticle, it can be found a mask blade, The mask blade is a shutter system with at least one blade, and it masks light outside the reticle image during a scan.
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